John Fenton Nightingale is Jack Fenton's ancestor from Salem, Massachusetts, in the 1600s.
In "Infinite Realms," when Danny, Tucker, Sam and Vlad get transported to Salem, Massachusetts in the 1600s by the Infi-map, John Fenton Nightingale appears among the mob surrounding Sam, who is tied up after being accused of witchcraft. He lays a ring of Blood Blossoms around Sam, and then puts a few blossoms in a sandwich, proving that they are edible.
He looks like Jack Fenton, but with longer hair. He wears a long orange overcoat, on top of the traditional clothes seen on the other residents of Salem. He also wears black gloves, and has a pocket watch with a gold chain.
Like many other residents of Salem in the 1600s, John Fenton Nightingale believes in witches, and even claims to be "Salem's Greatest Witch-Whacker." In addition to witches, he also hunts ghosts, just like his present-day descendant does. It is unknown how many witch- and ghost-hunting weapons and equipment he possesses, but he is known to have and be able to use Blood Blossoms.
Like his descendant Jack, John appears to be quite boisterous and obsessed with witch- and ghost-hunting. He is knowledgable about his work, but can come off as absent-minded.
- 302. "Infinite Realms"